1. Field of the Invention
The present invention relates generally to the field of beverage containers. More specifically the present invention relates to a self-cooling container apparatus containing a beverage or other food item and to methods of assembling and operating the apparatus. The terms "vessel contents", "food item" and "beverage" are considered equivalent for purposes of this application and are used interchangeably.
For the first preferred embodiment, the apparatus includes an outer container in the form of a can or bottle having a conventional unified bottom and side container wall terminating in an upper sealing flange referred to hereinafter as a container rim. A beverage retaining secondary vessel is provided within the container including a unified bottom and side vessel wall having at least one reversible bulge which protrudes inwardly to permit close fitting vessel insertion into the container during manufacture and which is caused to protrude outwardly after such insertion to maximize beverage retaining capacity and to increase vessel heat transfer surface area. The vessel has a vessel sealing flange, hereinafter referred to as a vessel rim, which extends laterally from the vessel wall and rests on top of the container rim. A narrow annular refrigerant chamber is defined between the container wall and vessel wall containing a refrigerant such as mixtures of hydrocarbons. Several reversible bulges are preferably provided.
2. Description of the Prior Art
There have previously been self-cooling containers for food items, these containers including refrigerant receptacles with widely spaced apart, rigid receptacle walls. The receptacle is opened when cooling is desired and the refrigerant is progressively discharged from the receptacle, extracting heat from the vessel contents. Problems with this construction have been high container expense, less than maximized heat transfer surface area and less than maximized beverage capacity.
It is thus an object of the present invention to provide a self-cooling container apparatus including an external container and an internal vessel for retaining a liquid food item, the container and vessel defining between them a refrigerant chamber with large heat transfer surface area and including beverage release means and an annular refrigerant release means.
It is another object of the present invention to provide such an apparatus in which regions of the internal vessel are configured as reversible bulges caused to protrude into the vessel for compact insertion into the external container and caused to protrude outwardly after such insertion to maximize beverage retaining capacity and to increase vessel heat transfer surface area.
It is still another object of the present invention to provide such an apparatus in which the refrigerant release means is simple and easy to use and in which the beverage release means cannot be manually operated until the refrigerant is released, and which shields surfaces over which the beverage flows during pouring against contamination.
It is a still further object of the invention to provide such an apparatus which functions as a thermos after refrigerant release and resultant beverage cooling, by defining an inner vessel spaced apart by an empty annular refrigerant chamber from the outer container, so that beverage not consumed immediately is kept cool while the outside of the container is a comfortably maintained at ambient temperature.
It is finally an object of the present invention to provide such an apparatus which is relatively inexpensive to manufacture, safe and easy to use.